CaCu3Ti4O12纳米陶瓷的制备及其介电机理研究

As a non-ferroelecric material, CaCu3Ti4O12 (CCTO) is in great demand for the miniaturization of electronic devices due to its high dielectric constant up to ~10000 with the good frequency- and temperature-independences. However, the origin of such high dielectric constant is controversially debated. CCTO ceramics with nanosized grains create a new view for exploring the origin of the high dielectric constant, except single crystals and ceramics with microsized grains. In this project, CCTO nanoceramics are fabricated by the molten salt and spark plasma sintering methods. The growth mechanism of CCTO nanopowders is studied to make sure the nanopowders is pure single crystalline CCTO phase. In addition, the CCTO grain growth mechanism during sintering is also investigated. We will systematically study the effects of microstructures on macroscopic dielectric properties of CCTO nanoceramics. More importantly, nanoscopic investigations on the structural, chemical and dielectric properties of CCTO nanoceramics are first carried out to explore the origin of high dielectric constant in CCTO. This project will establish the theoretical foundation for the preparation of high-performance CCTO nanoceramics, provide the scientific evidence to understand their dielectric behaviors, and make a significant contribution to the development of the electronics industry.

作为一种非铁电材料，CaCu3Ti4O12（CCTO）具有高达10000的介电常数，并且介电常数具有很好的频率和温度稳定性，满足了电子器件微型化方面的需求。然而，如此高介电常数的来源存在着争议。除了CCTO单晶和拥有微米晶粒的CCTO陶瓷，拥有纳米晶粒的CCTO陶瓷提供了一个全新的角度来探索高介电常数的来源。本项目使用熔盐合成法和放电等离子体烧结法来制备CCTO纳米陶瓷。通过研究CCTO纳米粉末的生长机理，确保纳米粉末是CCTO单晶相。此外，烧结过程中CCTO晶粒的生长机制也将被研究。我们将系统探索微观结构对CCTO纳米陶瓷的宏观介电性质的影响。更重要的是，首次通过对CCTO纳米陶瓷的形貌、成分以及电学性质进行纳米尺度上的测量揭示其高介电常数的来源。本项目将为制备高性能的CCTO纳米陶瓷提供理论基础，为理解其介电行为提供科学根据，为电子产业的发展做出重大贡献。

作为一种非铁电材料，CaCu3Ti4O12（CCTO）具有高达10000的介电常数，并且介电常数具有很好的频率和温度稳定性，满足了电子器件微型化方面的需求。然而，如此高介电常数的来源存在着争议。除了CCTO单晶和拥有微米晶粒的CCTO陶瓷，拥有纳米晶粒的CCTO陶瓷提供了一个全新的角度来探索高介电常数的来源。本项目使用熔盐合成法制备CCTO纳米粉末，研究CCTO纳米粉末的生长机理。此外，烧结过程中CCTO晶粒的生长机制也将被研究。我们将系统探索微观结构对CCTO纳米陶瓷的宏观介电性质的影响。本项目将为制备高性能的CCTO纳米陶瓷提供理论基础，为理解其介电行为提供科学根据，为电子产业的发展做出重大贡献。